Tatra 813

Tatra T813 was a truck produced in Czechoslovakia by the Tatra company.[1]

T 813
Overview
Manufacturer Tatra
Production 1967-1982
Body and chassis
Class Heavy Truck
Body style COE
Powertrain
Engine V12 multifuel
Dimensions
Length 8,800 mm (346.5 in) (T813 KOLOS)
Width 2,500 mm (98.4 in)
Height 2,780 mm (109.4 in) (T813 KOLOS)
Curb weight 14,000 kg (30,865 lb) (T813 KOLOS)
Chronology
Predecessor Tatra T141
Successor Tatra T815
T 930-xx E
Overview
Manufacturer Tatra
Also called T 930 E
Combustion chamber
Displacement 17,640 cc
Cylinder bore 120 mm (4.7 in)
Piston stroke 130 mm (5.1 in)
Cylinder block alloy Cast Iron
Cylinder head alloy Aluminium alloy
Valvetrain OHV
Compression ratio 16.5:1
Combustion
Fuel system Direct injection
Fuel type Diesel fuel
Cooling system Air-cooled
Output
Power output 198.6 kW (266 hp) @ 2000 rpm
Torque output 990 N·m (730 ft·lbf) @ 1300 rpm
Dimensions
Dry weight 1,035 kg (2,282 lb)

History

The first prototype already built in 1960 utilized existing Tatra T138 assemblies in 4x4 full-time all-wheel drive, which was also another first for Tatra. After the initial trials however the designers decided to develop and expand the concepts onto 8x8 all-wheel-drive all-terrain vehicle. The basis of the design thus became the modular chassis of T813. Successor is the Tatra T815 model.

Design and technology

The tubular backbone construction was once again selected. The main advantages of central load carrying backbone tube are in its high torsional and bending stiffness protecting the truck's body against load stresses. Another advantage is that it houses all important parts of the drive train as well as it enables a concept of modular construction where designers and customers can specify 4,6,8, wheel drive and various length wheelbase combinations. A new cab-over-engine design was implemented, as were the wide profile super single tyres and central tyre inflation/deflation system.

Engine

The naturally aspirated V12 engine T-930 was created by adding extra four cylinders to the existing T-928 75-degree V8 engine, used in Tatra T138. The crankshaft consisted of six individual journals bolted together with front and rear pins all running on the main roller bearings and located on axial friction thrust washers. The military version was once again multi-fuel capable, running on mixtures of diesel fuel, petrol and aviation kerosene fuel.

Chassis

The chassis is a full-length backbone tube with independent swing half axles in 4x4, 6x6 and 8x8. 4x4 models had front axle suspension via adjustable torsion bars, 6x6 and 8x8 models front and rear axles used longitudinal semi-elliptic leaf springs. For 4x4 configuration the rear axle was suspended via air suspension. Full-time all-wheel-drive front twin steer (6x6, 8x8) drive via homo-kinetic drive shafts, drive with the differential locks, inter-axle differentials with locks and planetary hub reductions on all models. Unlike many six-wheeled vehicles, which have a single front axle and tandem rear axles, 6x6 versions used twin steering front axles- as with the 8x8- and a single rear axle.

Transmission

The main gearbox was located behind the cabin and connected to the engine clutch housing via a short cardan shaft (this design enables a so-called flat floor cabin.) The main gearbox was bolted to an auxiliary gearbox, to a transfer case and then to a backbone tube and formed main part of a chassis structure. Options for the rear power take off and or a winch drive were available. Main and auxiliary gears were fully synchronized except the first and reverse gear. The new feature was unique 2-speed planetary overdrive system bolted between front and rear axles. The overdrive could only be selected manually whilst stationary. Auxiliary gearbox had a neutral position which allowed a winch and a power take off to use main gearbox gearing for variable speed operation. The final drives used Tatra gear differentials with locks, offset drive shafts and planetary hub reductions.

Brakes

Full triple circuit air "S" cam drum brakes acting on all wheels drums via slack adjuster, all brake cylinders were remotely vented. First brake circuit acts on front wheels, the second on rear wheels and the third controls trailer service brakes. Unique design feature was remotely mounted brake valve which was operated via hydraulic master and slave cylinder principle on the Hauler 6x6 or via mechanical linkage on 8x8 models.

T813 KOLOS military specs with dozer blade

Bodywork

Cabin is all steel construction of COE design but not tiltable, the access to the engine was provided via removable engine cowlings inside the cabin compartment. The cab came in two versions, the "short" two-seater two-door version and in the "long" "crew cab" seven seater four-door version. The military specs cabs included the roof hatch or two in the case of the crew cab. All cabs were equipped with self-contained diesel cab heater which could also be used in the winter to warm up the engine before starting it. Another military feature was CTI central tyre inflation system controlled from the cab for each wheel independently and an ability to pressurize gearbox and differentials housing during water crossing. The 8x8 models had abilility to cross trenches up to 1.4 metre wide and vertical obstacles up to 0.6 metre high. Water crossing depth (static including the wave) was up to 1.4 metre (KOLOS 8x8). The vehicle top speed was 92 km/h (NT & NTH), 80 km/h (KOLOS), 70 km/h (hauler), 60 km/h (S1) @ 2000 engine rpm.

Tare - 14,000 kg (KOLOS 8x8), 21,050 kg (Hauler 6x6), 11,200 kg (Chassis 8x8), 15,000 kg (S1 8x8), 7,000 kg (NT & NTH 4x4)
GVM - 22,200 kg(KOLOS 8x8), 22,000 kg (Hauler 6x6), 36,000 kg (Chassis 8x8), 36,000 kg (S1 8x8),
Max Trailer Mass - 65,000 kg (KOLOS 8x8), 100,000 kg (Hauler 6x6), 32,000 kg (NT & NTH 4x4
GCM - 79,000 kg (KOLOS 8x8), 121,050 kg (Hauler 6x6), 39,000 kg (NT & NTH 4x4)

Production

Production of Tatra T813 began in 1967 and was superseded by Tatra T815 in 1982. Models were available in the 4x4, 6x6, and 8x8 drive configurations for civilian and military use.

Sport

Tatra T813 at Truck trials @ Mohelnice, Czech Republic, May 2007.

T813 has become extremely popular after fall of the Iron Curtain in the West as an extreme off-road truck, participating at the various truck trials held across Europe.


References

Wikimedia Commons has media related to Tatra 813.
  1. ↑ Moderní Uźitkové Automobily TATRA kolektiv vývojove konstrukce N.P. Tatra Kopŕivnice 1979 Naśe Vojsko Praha, První vydání